GL5 Forum

Hi Folk's
I am ordering some boiler making materials.
The supplier is saying that gun metal has now been generally replaced as modern materials go by bronze.
He is asking if I want
sae660 leaded cast bronze
or
Pb102 hard drawn bronze (90% copper)
To make the
Main steam pipe (smoke box bush),
Main (boiler top steam collection bush).
Main (regulator and other) back head bushes.
Any advice on the choice of material I should choose would be most apreciated
Cheers.
Andy G.

Hi Andy

You should always use PB102 on boiler bushes. It needs sharp tools to cut and will grab on a slightly worn drill. Dormer A002 series drills are the best.

SAE660 is designed as a bearing metal, like Colphos, and the lead content is not a good idea for silver brazing. It does machine more easily.

Having said the above, in the past (and present) lots of people have undoubtedly been using the 'wrong' bronzes and probably got away with it.

Norm

Hi Norm
Thanks for the reply.
I will now let the supplier know the type required.
Thanks also for the additional information with regard to working with the material and choice of drill etc.
Best Wishes.
Andy G.

I normally use PB1 for my bushes

PB1 is good, PB102 is more readily available from suppliers.